Pulverized-fuel burner.



L. H, BERGMAN.

PULVERIZED FUEL BURNER. APPLICATION m'tu JULY is. 1915.

Patented Jan. 30, it.) I".

LAKE; H. BEBGIVEAN, F EHILhDELT-EHIJL PlE-JIEKNS'ETLVANZA.

PULVEEIZ'ED-3EUEL fipplicatlon filed July 16,

To all whom may concern:

Be it known that l, l ens ll. Bnucra'an, a subject of the King ofSweden, residing at vPhiladelphia, county of Philadelphia and State ofPennsylvania, have invented a new and useful Improvement inPulverizecl-Fuel Burners, of which the following is a .full, clear, andexact description, reference being had to the accompanying drawings,which form a part of this specification.

The invention relates to pulverized :luel burners for furnaces, boilersand kilns wherein air is employed both to atornize and propel the fueland to effect combustion.

The main object'of the invention is to so construct the burner as torequire only one source of air supply. This object is effected by aconstruction in which the common supply of air is so divided tl at partthereof used for combustion is supplied either on the outside or on theinside of the stream of air employed for atomizing and carrying thefuel. j i

In this application there is set forth and specifically claimed anembodiment of the invention wherein air of comparatively high pressureis used and wherein the combustion air takes a. path centrally withinthe stream of fuel atomizing and carrying air. In an. application ofeven date herewith, Serial No. 40,174, there is set forth andspecifically claimed a construction. wherein air of comparatively lowpressure is used and wl'ierein the combustion air takes a path centrallywithin the stream of fuel atoniizing and carrying air. In an applicationof even date herewith, Serial 1%. 40,172,

there is set forth and specifically ca -aimed a construction wherein thecombustion takes a path surrounding the passage for the fuel andatomizing and carrying air;

- the last-named application also claiming the subject-matter common toall arrangements. In the present patent I have also claimed thesuh1cct-n1atter common to the present application and Serial No. 4.0,17l.

In the drawings, which show a preferred embodiment of the invention,Figure'l is an elevation. of, and Fig. a vertical section through, theburner and fuel hopper.

The main pipe 7 of the burner has an inlet or hopper I) connected to apipe at, through which the fuel, fed thereinto in proper and uniformamount, by. any known means, drops by, gravit The rear wall 0Specification ct air may suitable distance iniront of the vertiuialfront wall of the hopper, forming a fuel delivery mouth 6.

Pipe 7 153 connected with a source of air supply provided with a. damper1% whereby the volume of air within. the burner may be regulated. Theforward part of piper is shown cylindrical, although it need notice soconstructed, its form depending on the desired shape of flame. The in orpipe dividing up the common source oi air sup ply is made in a separatepiece and is prel' erahly shaped conical at the rear end. .llae insideface of cone (Z extends for some distance toward the rear of the burner,afford ing in connection with the conical shape of the rear of pipe 5 agradually contracting; passage for the atomizing and propelling: airbefore it reaches the fuel delivered froiil the hopper, thereby causing;the air the forward. end of cone-d to build up a slightly higherpressure, insuring a maximum. speed of air through the opening 00. Thisope-1i mg is located at such distance in front of the fuel hopper Z)that the inducing; of the atomizing air will draw the fuel through thefuel delivery mouth e.

ll1e inner pipe 9 is arranged to slide lon gitudinally' upon supports jon the inner wall of pipe j", its sliding movement bein eliectcd bymeans of rod it. By adjusting the pipe {1 the area admitting'theatomizing he increased or decreased, thus increasing or decreasing thevolume or: store icing air to suit the varying amounts pulverized fuelused in the furnace.

From the foregoing description it will he understood that the pulverizedfuel is dropped through pipe (1 and hopper l5 and. air undercomparatively hi h pressure from a common source of supply is divided bymeans of inner pipe 9 into two streams, one-"the fuelv atoniizcing and.propelling air passing-within the annular space hetwecn the inner pipeand cone cl, this space being so located in relation to fuel hopper 6that 1 of said Having now fully described my what I claim and tersPatent is:

l. A pulverized fuel burner comprising an outer pipe having a rearextension adapted for communication with a source of air supply, aninner pipe open at its rear end toward the forward portion of said rearextension of the outer pipe and adapted to receive and convey a portionof said air to effect combustion and affording between it and the outerpipe an annular passage, open at its rear, for another portion of saidair to atomize and convey the fuel, and a fuel inlet to said passageinfront of the rear end. of the inner pipe.

2. A pulverized desire to protect by Letcommunication witha anopen-ended portion of said air affording between pipe an annularpassage, open at its rear, for another portion of said air to atomizeand convey the fuel, a fuel inlet to said passage in front of therearend of the inner pipe, and means to vary the area back of thefuel-inlet for admission of air to the annular fuel passage.

3. A pulverized fuel burner comprising an outer pipe having a rearextension adapted for communication with a source of air supply, anopen-ended inner pipe adapted to receive and convey a portion of saidair to effect combustion and affording between it and the outer pipe anannular passage, open at its rear, for another portion of said air toatomize and convey the fuel, a fuel inlet to said passage in front ofthe rear end of the inner pipe, and means to adjust the in nor pipe tovary the area back of the vfuel inlet for admission of air to theannular fuel passage. 1

4. A pulverized fuel burner comprising an outer pipe having a rearextension adapted for communication with a source of air supply, aninner pipe open at its rear end and adapted to receive and convey aportion of said air to effect combustion and affording between it andthe other pipe an annular passage, open at its rear, for another portionair to atomize and convey the fuel, said inner pipe being taperedinwardly toward its rear, and a fuel inlet to said passage.

5. A pulverized fuel burner comprising an outer pipe having a rearextension adapted for communication with a source of air supply, anopen-ended inner pipe adapted to receive and convey a portion of saidair to effect combustion and and the outer pipe an annular passage, openat its rear, for another portion of said air to atomize and convey thefuel, said inner pipe being tapered toward its rear, 2. fuel inletinvention,

I s u fuel burner comprising an outer pipe having a rear extension adaptouter casting fOl'llllIi-g' to said passage, and means to slide theinner pipe longitudinally and thereby vary the area back of the fuelinlet for admission of air to the annular fuel passage. I

6. A pulverized fuel burner comprising an. outer pipe having a rearextension adapted for communication with a source of air supply, anopen-ended inner pipe adapted to receive and convey a portion of saidair to wall forms part of said whose inner wall constitutes a part ofthe wall of said passage, there being a space between the front edge ofthe cone and the casting providing a mouth for the delivery of fuel fromthe hopper to said passage.

8. A-pulverized fuel burner comprising an open ended inner pipe, asurrounding an annular passage or fuel atomizing and conveying air, acommon air supply for both pipes, a fuel hopper, and a cone w 1086 outerwall forms part of said fuel hopper and whose inner Wall constitutes apart of the wall of said passage, there being a space between the frontedge of the cone and the casting providing a mouth for the delivery offuel from the hopper to said passage, the rear part of the inner pipetapering toward its rear end, it and the cone thereby affording betweenthem a gradually narrowing passage for the atomizing and conveying air'to said fuel delivery mouth.

9. A pulverized fuel burner comprising an outer pipe, an inner pipeinclosi-ng a combustion air passage and affording between it and theouter pipe a passage for fuel and for fuel atomizing and conveying air,an inlet for air common to both wipes, and a fuel hopper communicatingwith the space between said pipes, said pipes being arranged to form aforwardly contracting annular passage, back of said fuel inlet, whosemouth is located in front of the front wall of the hopper.

10. A pulverized fuel burner comprising an outer pipe, a fuel hopper, aninner pipe inclosing a combustion air passage and affording between itand the outer pipe a passage for fuel and for'fuel atomizing andconveying air, an inlet for air common to both. pipeS the outer pipehaving a conical portion whose front edge extends with the inner pipeforward of mnmeni v the front Wall of the hoppe: mi is specedl atomizingand conveying air, part of the from the outer pipe to afford afuelpaseage. inner pipe within the conical portion-0f the 11. Apulverized fuel burner comprising outer pipe converging rearwardly andafnn outer pipe having between its ends a- 'fording a forwardlycontracting passage for 1 eonicei portion spaced from the main Wall vthe passage of air towarolthe fuel inlet, and of the pipe, a fuel hoppercommunicating an inlet for aircormnonto both'pipes. with said space andWhose front Wall is back In testimony of which invention, I have of theforward edge of said conical portion, hereunto set-my hand, atPhiladelphia, on an inner pipe inclosing a combustion air this 14thday'of Jnly, 1915. I

passage and afiording between it and the enter pipe a passage for fueland. for fuel LABS

